An internal combustion engine in service generates crankcase gases, which form an aerosol mixture comprising oil drops in suspension in a gas. The oil drops originate from the splashing of the connecting rods and crankshaft in the oil contained in the oil tank. The gas originates from the leaks between the cylinders and the pistons; these leaks are sometimes called blow-by gas. Thus, it is necessary to separate the oil from the gas in order to re-inject the oil in the internal combustion engine.
US2008216660A1 describes an electrostatic filter for separating oil drops from a mixture of gas and oil. The electrostatic filter of US2008216660A1 comprises a separation chamber, an oil recovery chamber coupled to the separation chamber for the flowing of oil, an emitter electrode, collector electrode, and an electronic unit supplying the emitter electrode.
However, in the electrostatic filter of US2008216660A1, when the mixture is rich in oil, the oil captured by the collector electrode gathers on the collector electrode without being entirely discharged, thereby inducing a risk of clogging, hence of defect of the electrostatic filter. Furthermore, the oil gathered is hardly discharged on the collector electrode. However, the electrostatic charges gathered risk leading to an electric breakdown in the electrostatic filter, hence disabling the electrostatic filter.